Kelsey Grammar plays a wayward Navy officer, Tom Dodge, who is notorious throughout the Navy for having responded to a close call involving a Russian submarine by getting drunk and tattooing "welcome aboard" on an unmentionable appendage. He gets assigned by Admiral Winslow (Rip Torn) to command his own submarine; unfortunately, this sub is a rusting 1958 diesel model that the Navy wants to engage in war games to find out if it could inflict any damage. The assumption is, this sub is comparable to those the Russians are selling to renegade Iraqi and Libyan commanders, who might use them on suicide missions against the US.

Once on board, we meet the cast of quirky characters who will man this clunker, including a hyper, mutinous Rob Schneider as second in command, Harland Williams as the copulating whale-impersonating radar operater Sonar, and Lauren Holly as the token female officer. The slapstick ensues as this group of underdogs attempt to pull off the impossible, the completion of which will determine Dodge's future career.